Dual sharpener



FIG. 1 is a side elevational view of one side, the other side being identical, the sharpening rods in phantom not being part of the claimed design;

FIG. 2 is a top plan view thereof; the sharpening rods in phantom not being part of the claimed design;

FIG. 3 is a bottom plan view thereof, the sharpening rod in phantom not being part of the claimed design;

FIG. 4 is a front elevational view thereof, the sharpening rod in phantom not being part of the claimed design; and,

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a dual sharpener, as shown and described. 